Chapter 9, Problem 137A

Interpretation Introduction

Interpretation:

The given chemical equation needs to be completed and whether a precipitate forms or not needs to be identified.

$\text{Ca}{\left({\text{NO}}_{\text{3}}\right)}_2\left(\text{aq}\right){\text{+Na}}_2{\text{CO}}_3\left(\text{aq}\right)\to$

Concept introduction:

If two solutions are mixed, the ions in the resulting solution may react with each other. A double displacement reaction may take place. This can result in the formation of a precipitate, water and gas.

Answer to Problem 137A

The reaction occurs and a precipitate of ${\text{CaCO}}_{\text{3}}$ is formed.

$\text{Ca}{\left({\text{NO}}_{\text{3}}\right)}_2\left(\text{aq}\right){\text{+Na}}_2{\text{CO}}_3\left(\text{aq}\right)\to {\text{2NaNO}}_{\text{3}}\left(\text{aq}\right){\text{+CaCO}}_{\text{3}}\left(\text{s}\right)$

Explanation of Solution

The first product in this reaction is sodium nitrate and second one is ${\text{CaCO}}_{\text{3}}$. According to the solubility rule given in the table, carbonates are insoluble.

Therefore, ${\text{CaCO}}_{\text{3}}$ precipitate out in this reaction and the reaction does occur.

$\text{Ca}{\left({\text{NO}}_{\text{3}}\right)}_2\left(\text{aq}\right){\text{+Na}}_2{\text{CO}}_3\left(\text{aq}\right)\to {\text{2NaNO}}_{\text{3}}\left(\text{aq}\right){\text{+CaCO}}_{\text{3}}\left(\text{s}\right)$

Conclusion

A precipitation reaction takes place when the combination of ions in the solution results in the formation of a compound which is not soluble in water.